The Health Protection Agency (HPA), UK, has reported a 10-fold increase in measles cases this year, as compared to the numbers last year. Many cases are reported to be clustered in universities and schools (http://www.bbc.co.uk/news/uk-england-kent-15122908). This underscores the need for rapid and accurate diagnosis for surveillance of the disease. In this context, the performance of a newly developed point-of-care test (POCT) for the detection of measles-specific IgM antibodies in serum and oral fluid specimens was evaluated in a recent study (Bull. World Health Organ. 2011 Sep 1;89(9):675-82). The study also attempted to determine whether measles virus nucleic acid could be recovered from used POCT strips for genotyping. It concluded that the POCT has the sensitivity and specificity required of a field-based test for measles diagnosis, and that measles virus nucleic acid could be recovered from POCT strips after storage for 5 weeks at 20-25 ΀C.

Toxoplasmosis is often an under-reported disease. To determine the incidence of congenital toxoplasmosis in Colombian newborns, 15,333 samples from umbilical cord blood between March 2009 and May 2010 were collected in 19 different hospitals and maternal-child health services from 7 different cities in Columbia. An IgM ELISA assay was used, and confirmed by western blot and a repeat ELISA IgM assay. In a sub-sample of 1613 children that were found to be negative by the anti-Toxoplasma IgM assay, the frequency of specific anti-Toxoplasma IgA was determined. Congenital toxoplasmosis infection was confirmed in 15 children: 7 were symptomatic, and 3 of them died before the first month of life. A significant correlation was found between a high incidence of markers for congenital toxoplasmosis and higher mean annual rainfall in the area.

Six patients and an employee at the Kenneth E. Spencer Memorial Home in Moncton, Canada, have been reported to be infected with Salmonellosis More Details in an outbreak in September this year. Following the outbreak, one resident at the facility died (http://news.ca.msn.com/local/newbrunswick/seven-infected-one-dead-from-nursing-home- Salmonella More Details). Mathematical models that estimate the proportion of food-borne illnesses attributable to food commodities at specific points in the food chain may be useful to risk managers and policy makers to formulate public health goals, prioritize interventions, and document the effectiveness of mitigations aimed at reducing illness. Using human surveillance data on laboratory-confirmed Salmonella infections from the Centres for Disease Control and Prevention and Salmonella testing data from the U.S. Department of Agriculture Food Safety and Inspection Service's regulatory programs, a point-of-processing food-borne illness attribution model was developed by adapting the Hald Salmonella Bayesian source attribution model (Foodborne Pathog. Dis. 2011 Apr;8(4):509-16). The adapted model shows promise and may serve as a basis for an approach to food safety decision-making.

On 2 September 2011, the Colorado Department of Public Health and Environment (CDPHE) notified CDC of seven cases of listeriosis reported since 28 August 2011. By 6 September 2011, all seven Colorado patients interviewed with the Listeria Initiative questionnaire reported eating cantaloupe (a type of melon) in the month before illness began. (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm60e0930a1.htm?s_cid=mm60e0930a1_w)Listeria monocytogenes nes is essentially an intracellular pathogen. The virulence of the pathogen depends on its capacity to escape from the phagosome into the host cytosol, where the bacteria replicate. A study suggests that Listeria exploits mechanisms of cellular ion homeostasis to escape the phagosome (Proc. Natl Acad. Sci. U S A 2011 Jan 25;108(4):1633-8). This indicates that host ion-channels may function as key parameters of bacterial virulence in Listeria infections. Be that as it may, as always, prevention is better than cure. Recommendations for prevention of listeriosis are available at http://www.cdc.gov/listeria.

An ongoing outbreak of encephalitis in Eastern Uttar Pradesh is a cause of concern (http://news24online.com/8-more-dead-in-UP;-encephalitis-toll-rises-to-376_News24_34617.aspx). In an attempt to understand the complex biological processes of host response during the progression of Japanese encephalitis, a group of investigators administered the virus subcutaneously in mice and harvested the brain for whole genome expression profiling by cDNA microarray (Virol. J. 2011;8:92.). Interestingly, the transcription profile revealed significant differential expression of various patterns of recognition receptors and chemotactic genes, with an activation of the inflammasome. It was postulated that the resultant increased leukocyte infiltration and aggravated CNS inflammation may be the cause of disease severity.

The number of deaths due to definite or probable variant Creutzfeldt Jacob Disease (vCJD) as of 3 October 2011 has risen to 173. A total of 3 definite/probable patients remain alive, so the total number of definite or probable vCJD cases (dead and alive) is 176. The overall picture remains consistent with the view that the vCJD outbreak in the UK is in decline, albeit now with a pronounced tail. The first cases were observed in 1995, and the peak number of deaths was 28 in the year 2000, followed by 20 in 2001, 17 in 2002, 18 in 2003, 9 in 2004, 5 in 2005, 5 in 2006, 5 in 2007, 1 in 2008, 3 in 2009, 3 in 2010, and now 2 so far in 2011 http://www.cjd.ed.ac.uk/figures.htm. A recent review, however, warns of the possibility of an increased incubation period in older patients and those with PRNP-129 MV and W genotypes exposed in the dietary at-risk period. Early diagnosis of such patients remains important to reduce the possibility of secondary transmission of the condition via blood donation or surgical procedures. An effective screening test, preferably from blood, is yet to be developed (Int. J. Mol. Epidemiol. Genet. 2011 August 30;2(3):217-27).

Malaria continues to be rampant in Africa. Health officials in Unity state of Sudan have reported 10 deaths following a recent increase in malaria cases (http://www.sudantribune.com/Malaria-outbreak-kills-10-in,40291). A case control study in Uganda compared children with and without HIV-1 infection and found that the age-adjusted odds of HIV seropositivity among children with cerebral malaria compared to the control groups (children with uncomplicated malaria and no malaria) was 4.98 (95% CI 1.54-16.07), P-value = 0.003 (BMC Pediatr. 2011;11:5.).

Despite the lack of any kind of objective evidence of the clinical utility of commercial serological tests for tuberculosis, they are routinely used in our country as a tool for laboratory diagnosis of tuberculosis. In an attempt to curb the use of these inappropriate tests, in July 2011, the WHO published a policy statement on commercial serodiagnostic tests for diagnosis of TB. The policy states that 'Commercial serological tests provide inconsistent and imprecise estimates of sensitivity and specificity. There is no evidence that existing commercial serological assays improve patient-important outcomes, and high proportions of false-positive and false-negative results adversely impact patient safety. Overall data quality was graded as very low, with harms/risks far outweighing any potential benefits (strong recommendation). It is therefore recommended that these tests should not be used in individuals suspected of active pulmonary or extra-pulmonary TB, irrespective of their HIV status'. The WHO policy strongly encourages targeted further research to identify new/alternative point-of-care tests for TB diagnosis and/or serological tests with improved accuracy (http://www.who.int/tb/laboratory/policy_statement/en).

With much ado about early diagnosis and treatment of tuberculosis, it is important to understand the natural course of the disease in HIV-negative individuals. The prognosis, specifically the case fatality and duration, of untreated TB is important since they are key parameters in interpreting epidemiological data. A review analysed studies from the pre-chemotherapy era. It was found that untreated smear-positive tuberculosis among HIV-negative individuals has a 10-year case fatality variously reported between 53% and 86%, with a weighted mean of 70%. Ten-year case fatality of culture-positive smear-negative TB was not reported directly but could be indirectly estimated to be approximately 20%. The duration of TB from the onset to cure or death was found to be approximately 3 years and appeared similar for smear-positive and smear-negative TB (PLoS One 2011;6(4):e17601).

The WHO has endorsed the Xpert MTB/RIF assay for investigation of patients suspected of having TB. However, its utility for routine TB screening and detection of rifampicin resistance among HIV-infected patients with advanced immunodeficiency enrolling in antiretroviral therapy (ART) services is unknown. In this context, a study assessed the accuracy of the Xpert MTB/RIF assay for diagnosing TB and drug resistance in adult HIV-infected patients with no current TB diagnosis, enrolled in an ART clinic in a South African township (PLoS Med. 2011 July;8(7):e1001067). In this population of individuals at high risk of TB, intensive screening using the Xpert MTB/RIF assay increased case detection by 45% compared with smear microscopy, strongly supporting replacement of microscopy for this indication. However, despite the ability of the assay to rapidly detect rifampicin-resistant disease, the specificity for drug-resistant TB was sub-optimal.